1. Technical Field
The subject matter of this disclosure generally relates to the field of implantable medical devices. More specifically, the present disclosure relates to reducing compensation in tissue stimulation therapy, and particularly electrical neurostimulation therapy.
2. Background Information
Implantable medical devices (IMDs) are used to treat a variety of diseases and disorders. Some types of IMDs apply an electrical signal to a patient's body tissue to which the IMD is coupled. For example, a neurostimulator can be coupled to a patient's vagus nerve to provide an electrical signal to the nerve to treat seizure disorders such as epilepsy. Providing an electrical signal to the vagus nerve can also be therapeutically beneficial to treat other conditions, including depression and various eating disorders such as bulimia nervosa.
The body is known to compensate or alter its response to repeated stimuli. For example, after receiving an electrical neurostimulation therapy over an extended period of time, the body may adapt or compensate in response to the repeated application of the electrical signal, thereby rendering the therapy provided by the IMD less beneficial. When this happens, a healthcare provider may adjust the operation of the IMD. An IMD adjustment may involve altering one or more operating parameters that define the electrical signal, such as current amplitude, pulse width, pulse frequency, on time, off time, etc. After the adjustment has been made to the electrical parameter(s), the body eventually may again compensate to the therapy provided by the IMD, thereby again rendering the therapy provided by the IMD less beneficial. Numerous adjustments may thus be required because the body may continually compensate to the therapy. Each IMD adjustment usually requires a visit to the physician that, for many patients, is time-consuming, expensive, and generally undesirable.